mfd: Add Raspberry Pi Sense HAT core driver

mfd: Add rpi_sense_core of compatible string

rpisense-fb: Set pseudo_pallete to prevent crash on fbcon takeover

Signed-off-by: Serge Schneider <[email protected]>

rpisense-fb: Add explicit fb_deferred_io_mmap hook

As of commit [1], introduced in 5.18, fbdev drivers that use
deferred IO and need mmap support must include an explicit fb_mmap
pointer to the fb_deferred_io_mmap.

Signed-off-by: Phil Elwell <[email protected]>

[1] 5905585 ("fbdev: Put mmap for deferred I/O into drivers")

drivers/input/joystick/Kconfig

@@ -422,4 +422,12 @@ config JOYSTICK_SEESAW
 	  To compile this driver as a module, choose M here: the module will be
 	  called adafruit-seesaw.
 
+config JOYSTICK_RPISENSE
+	tristate "Raspberry Pi Sense HAT joystick"
+	depends on GPIOLIB && INPUT
+	select MFD_RPISENSE_CORE
+
+	help
+	  This is the joystick driver for the Raspberry Pi Sense HAT
+
 endif

drivers/input/joystick/Makefile

@@ -41,3 +41,4 @@ obj-$(CONFIG_JOYSTICK_WARRIOR)		+= warrior.o
 obj-$(CONFIG_JOYSTICK_WALKERA0701)	+= walkera0701.o
 obj-$(CONFIG_JOYSTICK_XPAD)		+= xpad.o
 obj-$(CONFIG_JOYSTICK_ZHENHUA)		+= zhenhua.o
+obj-$(CONFIG_JOYSTICK_RPISENSE)		+= rpisense-js.o

drivers/input/joystick/rpisense-js.c

@@ -0,0 +1,153 @@
+/*
+ * Raspberry Pi Sense HAT joystick driver
+ * http://raspberrypi.org
+ *
+ * Copyright (C) 2015 Raspberry Pi
+ *
+ * Author: Serge Schneider
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ *
+ */
+
+#include <linux/module.h>
+
+#include <linux/mfd/rpisense/joystick.h>
+#include <linux/mfd/rpisense/core.h>
+
+static struct rpisense *rpisense;
+static unsigned char keymap[5] = {KEY_DOWN, KEY_RIGHT, KEY_UP, KEY_ENTER, KEY_LEFT,};
+
+static void keys_work_fn(struct work_struct *work)
+{
+	int i;
+	static s32 prev_keys;
+	struct rpisense_js *rpisense_js = &rpisense->joystick;
+	s32 keys = rpisense_reg_read(rpisense, RPISENSE_KEYS);
+	s32 changes = keys ^ prev_keys;
+
+	prev_keys = keys;
+	for (i = 0; i < 5; i++) {
+		if (changes & 1) {
+			input_report_key(rpisense_js->keys_dev,
+					 keymap[i], keys & 1);
+		}
+		changes >>= 1;
+		keys >>= 1;
+	}
+	input_sync(rpisense_js->keys_dev);
+}
+
+static irqreturn_t keys_irq_handler(int irq, void *pdev)
+{
+	struct rpisense_js *rpisense_js = &rpisense->joystick;
+
+	schedule_work(&rpisense_js->keys_work_s);
+	return IRQ_HANDLED;
+}
+
+static int rpisense_js_probe(struct platform_device *pdev)
+{
+	int ret;
+	int i;
+	struct rpisense_js *rpisense_js;
+
+	rpisense = rpisense_get_dev();
+	rpisense_js = &rpisense->joystick;
+
+	INIT_WORK(&rpisense_js->keys_work_s, keys_work_fn);
+
+	rpisense_js->keys_dev = input_allocate_device();
+	if (!rpisense_js->keys_dev) {
+		dev_err(&pdev->dev, "Could not allocate input device.\n");
+		return -ENOMEM;
+	}
+
+	rpisense_js->keys_dev->evbit[0] = BIT_MASK(EV_KEY);
+	for (i = 0; i < ARRAY_SIZE(keymap); i++) {
+		set_bit(keymap[i],
+			rpisense_js->keys_dev->keybit);
+	}
+
+	rpisense_js->keys_dev->name = "Raspberry Pi Sense HAT Joystick";
+	rpisense_js->keys_dev->phys = "rpi-sense-joy/input0";
+	rpisense_js->keys_dev->id.bustype = BUS_I2C;
+	rpisense_js->keys_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
+	rpisense_js->keys_dev->keycode = keymap;
+	rpisense_js->keys_dev->keycodesize = sizeof(unsigned char);
+	rpisense_js->keys_dev->keycodemax = ARRAY_SIZE(keymap);
+
+	ret = input_register_device(rpisense_js->keys_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not register input device.\n");
+		goto err_keys_alloc;
+	}
+
+	ret = gpiod_direction_input(rpisense_js->keys_desc);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not set keys-int direction.\n");
+		goto err_keys_reg;
+	}
+
+	rpisense_js->keys_irq = gpiod_to_irq(rpisense_js->keys_desc);
+	if (rpisense_js->keys_irq < 0) {
+		dev_err(&pdev->dev, "Could not determine keys-int IRQ.\n");
+		ret = rpisense_js->keys_irq;
+		goto err_keys_reg;
+	}
+
+	ret = devm_request_irq(&pdev->dev, rpisense_js->keys_irq,
+			       keys_irq_handler, IRQF_TRIGGER_RISING,
+			       "keys", &pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "IRQ request failed.\n");
+		goto err_keys_reg;
+	}
+	return 0;
+err_keys_reg:
+	input_unregister_device(rpisense_js->keys_dev);
+err_keys_alloc:
+	input_free_device(rpisense_js->keys_dev);
+	return ret;
+}
+
+static int rpisense_js_remove(struct platform_device *pdev)
+{
+	struct rpisense_js *rpisense_js = &rpisense->joystick;
+
+	input_unregister_device(rpisense_js->keys_dev);
+	input_free_device(rpisense_js->keys_dev);
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id rpisense_js_id[] = {
+	{ .compatible = "rpi,rpi-sense-js" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, rpisense_js_id);
+#endif
+
+static struct platform_device_id rpisense_js_device_id[] = {
+	{ .name = "rpi-sense-js" },
+	{ },
+};
+MODULE_DEVICE_TABLE(platform, rpisense_js_device_id);
+
+static struct platform_driver rpisense_js_driver = {
+	.probe = rpisense_js_probe,
+	.remove = rpisense_js_remove,
+	.driver = {
+		.name = "rpi-sense-js",
+		.owner = THIS_MODULE,
+	},
+};
+
+module_platform_driver(rpisense_js_driver);
+
+MODULE_DESCRIPTION("Raspberry Pi Sense HAT joystick driver");
+MODULE_AUTHOR("Serge Schneider <[email protected]>");
+MODULE_LICENSE("GPL");

drivers/mfd/Kconfig

@@ -11,6 +11,14 @@ config MFD_CORE
 	select IRQ_DOMAIN
 	default n
 
+config MFD_RPISENSE_CORE
+	tristate "Raspberry Pi Sense HAT core functions"
+	depends on I2C
+	select MFD_CORE
+	help
+	  This is the core driver for the Raspberry Pi Sense HAT. This provides
+	  the necessary functions to communicate with the hardware.
+
 config MFD_CS5535
 	tristate "AMD CS5535 and CS5536 southbridge core functions"
 	select MFD_CORE

drivers/mfd/Makefile

@@ -268,6 +268,7 @@ obj-$(CONFIG_MFD_STMFX) 	+= stmfx.o
 obj-$(CONFIG_MFD_KHADAS_MCU) 	+= khadas-mcu.o
 obj-$(CONFIG_MFD_ACER_A500_EC)	+= acer-ec-a500.o
 obj-$(CONFIG_MFD_QCOM_PM8008)	+= qcom-pm8008.o
+obj-$(CONFIG_MFD_RPISENSE_CORE)	+= rpisense-core.o
 
 obj-$(CONFIG_SGI_MFD_IOC3)	+= ioc3.o
 obj-$(CONFIG_MFD_SIMPLE_MFD_I2C)	+= simple-mfd-i2c.o

drivers/mfd/rpisense-core.c

@@ -0,0 +1,163 @@
+/*
+ * Raspberry Pi Sense HAT core driver
+ * http://raspberrypi.org
+ *
+ * Copyright (C) 2015 Raspberry Pi
+ *
+ * Author: Serge Schneider
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ *
+ *  This driver is based on wm8350 implementation.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/rpisense/core.h>
+#include <linux/slab.h>
+
+static struct rpisense *rpisense;
+
+static void rpisense_client_dev_register(struct rpisense *rpisense,
+					 const char *name,
+					 struct platform_device **pdev)
+{
+	int ret;
+
+	*pdev = platform_device_alloc(name, -1);
+	if (*pdev == NULL) {
+		dev_err(rpisense->dev, "Failed to allocate %s\n", name);
+		return;
+	}
+
+	(*pdev)->dev.parent = rpisense->dev;
+	platform_set_drvdata(*pdev, rpisense);
+	ret = platform_device_add(*pdev);
+	if (ret != 0) {
+		dev_err(rpisense->dev, "Failed to register %s: %d\n",
+			name, ret);
+		platform_device_put(*pdev);
+		*pdev = NULL;
+	}
+}
+
+static int rpisense_probe(struct i2c_client *i2c)
+{
+	int ret;
+	struct rpisense_js *rpisense_js;
+
+	rpisense = devm_kzalloc(&i2c->dev, sizeof(struct rpisense), GFP_KERNEL);
+	if (rpisense == NULL)
+		return -ENOMEM;
+
+	i2c_set_clientdata(i2c, rpisense);
+	rpisense->dev = &i2c->dev;
+	rpisense->i2c_client = i2c;
+
+	ret = rpisense_reg_read(rpisense, RPISENSE_WAI);
+	if (ret > 0) {
+		if (ret != 's')
+			return -EINVAL;
+	} else {
+		return ret;
+	}
+	ret = rpisense_reg_read(rpisense, RPISENSE_VER);
+	if (ret < 0)
+		return ret;
+
+	dev_info(rpisense->dev,
+		 "Raspberry Pi Sense HAT firmware version %i\n", ret);
+
+	rpisense_js = &rpisense->joystick;
+	rpisense_js->keys_desc = devm_gpiod_get(&i2c->dev,
+						"keys-int", GPIOD_IN);
+	if (IS_ERR(rpisense_js->keys_desc)) {
+		dev_warn(&i2c->dev, "Failed to get keys-int descriptor.\n");
+		rpisense_js->keys_desc = gpio_to_desc(23);
+		if (rpisense_js->keys_desc == NULL) {
+			dev_err(&i2c->dev, "GPIO23 fallback failed.\n");
+			return PTR_ERR(rpisense_js->keys_desc);
+		}
+	}
+	rpisense_client_dev_register(rpisense, "rpi-sense-js",
+				     &(rpisense->joystick.pdev));
+	rpisense_client_dev_register(rpisense, "rpi-sense-fb",
+				     &(rpisense->framebuffer.pdev));
+
+	return 0;
+}
+
+static void rpisense_remove(struct i2c_client *i2c)
+{
+	struct rpisense *rpisense = i2c_get_clientdata(i2c);
+
+	platform_device_unregister(rpisense->joystick.pdev);
+}
+
+struct rpisense *rpisense_get_dev(void)
+{
+	return rpisense;
+}
+EXPORT_SYMBOL_GPL(rpisense_get_dev);
+
+s32 rpisense_reg_read(struct rpisense *rpisense, int reg)
+{
+	int ret = i2c_smbus_read_byte_data(rpisense->i2c_client, reg);
+
+	if (ret < 0)
+		dev_err(rpisense->dev, "Read from reg %d failed\n", reg);
+	/* Due to the BCM270x I2C clock stretching bug, some values
+	 * may have MSB set. Clear it to avoid incorrect values.
+	 * */
+	return ret & 0x7F;
+}
+EXPORT_SYMBOL_GPL(rpisense_reg_read);
+
+int rpisense_block_write(struct rpisense *rpisense, const char *buf, int count)
+{
+	int ret = i2c_master_send(rpisense->i2c_client, buf, count);
+
+	if (ret < 0)
+		dev_err(rpisense->dev, "Block write failed\n");
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rpisense_block_write);
+
+static const struct i2c_device_id rpisense_i2c_id[] = {
+	{ "rpi-sense", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, rpisense_i2c_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id rpisense_core_id[] = {
+	{ .compatible = "rpi,rpi-sense" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, rpisense_core_id);
+#endif
+
+
+static struct i2c_driver rpisense_driver = {
+	.driver = {
+		   .name = "rpi-sense",
+		   .owner = THIS_MODULE,
+	},
+	.probe = rpisense_probe,
+	.remove = rpisense_remove,
+	.id_table = rpisense_i2c_id,
+};
+
+module_i2c_driver(rpisense_driver);
+
+MODULE_DESCRIPTION("Raspberry Pi Sense HAT core driver");
+MODULE_AUTHOR("Serge Schneider <[email protected]>");
+MODULE_LICENSE("GPL");
+

drivers/video/fbdev/Kconfig

@@ -1839,6 +1839,19 @@ config FB_SM712
 	  called sm712fb. If you want to compile it as a module, say M
 	  here and read <file:Documentation/kbuild/modules.rst>.
 
+config FB_RPISENSE
+	tristate "Raspberry Pi Sense HAT framebuffer"
+	depends on FB
+	select MFD_RPISENSE_CORE
+	select FB_SYS_FOPS
+	select FB_SYS_FILLRECT
+	select FB_SYS_COPYAREA
+	select FB_SYS_IMAGEBLIT
+	select FB_DEFERRED_IO
+
+	help
+	  This is the framebuffer driver for the Raspberry Pi Sense HAT
+
 source "drivers/video/fbdev/omap/Kconfig"
 source "drivers/video/fbdev/omap2/Kconfig"
 source "drivers/video/fbdev/mmp/Kconfig"

drivers/video/fbdev/Makefile

@@ -125,6 +125,7 @@ obj-$(CONFIG_FB_OF)               += offb.o
 obj-$(CONFIG_FB_DA8XX)		  += da8xx-fb.o
 obj-$(CONFIG_FB_SSD1307)	  += ssd1307fb.o
 obj-$(CONFIG_FB_SIMPLE)           += simplefb.o
+obj-$(CONFIG_FB_RPISENSE)	  += rpisense-fb.o
 
 # the test framebuffer is last
 obj-$(CONFIG_FB_VIRTUAL)          += vfb.o